Thanks Kynoch, that's exactly the sort of stuff I'd like to know; and I think TH44 your suggestion of the .690" round ball may be a good starting point. Now just to work on powder charge, wadding and patching.

Tinker, I have pics from the dealer, but no idea how and where to post them since photobucket shot itself in the foot. In short, it's a plain-looking toplever, bar action hammer gun with a straight stock, yet it has some stylish touches, like drop points on the stock head, better than average walnut, and shell fences for the hammers to fall into. It has steel barrels; damascus is normally my thing, but I couldn't pass up the opportunity for a play with a ball-and-shot gun for under AUD 1,000...